Whether it was a decree of the Latin confederacy, or the genius and insight of some unknown founder, or the natural development of commerce, which called the city of Rome into existence, we have not even grounds to conjecture. But there is another point to be observed in connection with the position of Rome as the emporium of Latium. When history begins to dawn upon us Rome stands in contrast to the league of the Latin communities as a single enclosed city. The Latin custom of dwelling in open villages and only using the common town as a fortress and place of assembly or in time of need, was, in all probability, far sooner restricted in the Roman province than anywhere else in Latium. Not that the Roman had ceased to manage his farm himself, or to regard it as his real home; but already the unhealthiness of the country air had had the effect of inducing him to fix his abode on the more airy and healthy heights of the town; and with the farmers a numerous non-agricultural population of foreigners and natives must have been established there for a long time. This to some extent accounts for the dense population of the Roman territory, which at most can only be reckoned as extending over 115 square miles of soil, part of it marsh and sand, and yet, according to the city’s oldest constitution, furnished a city militia of thirty-three hundred freemen, and therefore must have counted at least ten thousand free inhabitants. But there is something more. Everyone acquainted with the Romans and their history is aware that the peculiarity of their public and private existence lies in their municipal and commercial life, and that the distinction between them and other Latins, and Italian nations generally, is before all the distinction between the citizen and the farmer. It is true that Rome was not a mercantile city like Corinth or Carthage; for Latium is an essentially agricultural district and Rome was, and remained, above everything a Latin town. But the distinction of Rome above the crowd of other Latin towns must still be referred to her commercial position and to the influence of that position upon the character of her citizens. If Rome was the emporium of the Latin district, it is easy to understand that here, over and above the Latin husbandry, a vigorous municipal life quickly developed itself and so laid the foundation of her pre-eminence. The tracing of the course of this mercantile and strategic development of the city of Rome is far more important and far easier than the thankless task of making a chemical analysis of the insignificant and very similar communities of antiquity; we can follow this development to some extent in the traditions concerning these successive walls and fortifications of Rome, whose erection must have gone hand in hand with the advance of the Roman commonwealth to importance as a city.